The present invention relates to a method of checking the existence of a pipeline connection between two end points.
Each type of cigarette consists of a unique tobacco blend which is transferred from a tobacco distributing place (feeder) by pipelines to the cigarette manufacturing machines (rod makers) by vacuum. In production plants in which several rod makers are simultaneously in operation there are therefore a large number of pipelines. Since at times, and frequently every day, new tobacco blends for the manufacture of cigarettes are required in the rod makers, the pipelines are frequently disconnected and reconnected, which easily leads to incorrect pipeline connections due to the difficulty in viewing the many pipelines. This difficulty in viewing the pipelines is further increased by the fact that rod makers and feeders are customarily located in different rooms or floors and therefore there are relatively large distances between them of, in some cases, more than 100 meters.
In order to avoid incorrect associations between feeder and rod maker leading to errors in production, the pipeline can be checked visually. However this requires a relatively large amount of work and furthermore is not an absolutely reliable method of verification due to the difficulty in viewing the pipelines. Another possibility of checking the pipe connections is to apply pressure. For this purpose however, closure caps must be placed on the end of the pipe, representing a resistance to flow upon the subsequent conveyance of the tobacco and leading to damage to the tobacco. The pipe connection can also be checked by applying a vacuum. However, it has been found with this method that the measurement instruments become clogged in the course of time by tobacco dust which settles out and that they thus become inoperable. Furthermore, under certain circumstances incorrect tobacco already in the pipeline may be conveyed by the application of a vacuum.